The Hollywood star - who has previously confessed to having the skin-smoothing injections once before, but didn't like the results - hates how it takes the character from people's faces and leaves them expressionless.
She said: "You see women and you know they're not young but you can't tell how old they are. It makes them look harder. The warmth in their face goes away. It is not a good look."
Instead of cosmetic surgery, the 40-year-old actress credits her youthful appearance and slim figure to a healthy diet.
Jennifer - whose ex-husband is Brad Pitt - insists it is vital to look good if you want to have a successful career on the big screen.
She explained: "I'm a realist. If I eat burgers and fries everyday I won't get the parts I'm offered. I'd become a character actress, that might be fine one day but not right now. "
Jennifer recently admitted she doesn't pay any attention to how she looks.
She said: "I don't think a lot about my physical appearance. It is what it is and I can't control it. I pay attention to the extent that I put on clothes today, I decided which shoes to wear with them and I even combed my hair! But apart from that, I just feel I am what I am."